Ethioninine and 2-Fluoroacetamide will be fed to rats and the normal liver tissue, pre-malignant nodule and hepatomas will be analyzed for free fatty aldehydes, fatty alcohols and glycerol ethers to determine if these lipid types are altered in these three tissues as compared to control animals. Enzyme involved in the metabolism of free fatty aldehydes, fatty alcohols and glycerol ethers will be isolated and characterized in these three types of liver tissue to determine if a change in enzyme function accounts for the results obtained.